1. Field of the Invention
The invention relates to an in-vivo observing system and an in-vivo observing method for observing inside of an organ of a subject such as a patient.
2. Description of the Related Art
Conventionally, in a field of an endoscope, there are capsule endoscopes which are introduced into an organ of a subject to capture an image (hereinafter, called also an in-vivo image) inside of the organ. The capsule endoscope includes an imaging function and a radio communication function in a capsule casing and functions as an in-vivo image acquisition device for obtaining a group of in-vivo images of a subject. The capsule endoscope is swallowed through a mouth of a subject such as a patient, then sequentially captures in-vivo images of the subject while moving in a gastrointestinal tract by a peristaltic movement and the like during a period until it is naturally discharged to the outside of the subject and sequentially wirelessly transmits the captured in-vivo images to a receiving device outside of the subject.
The receiving device is carried by the subject, receives a group of in-vivo images from the capsule endoscope in the subject, and accumulates the received group of the in-vivo images to a detachable storage medium. The storage medium in which the group of the in-vivo images is accumulated is removed from the receiving device and inserted into a predetermined image display device. The image display device obtains the group of the in-vivo images of the subject through the storage medium and displays the group of the in-vivo images of the subject on a display. A user such as a doctor and a nurse examines inside of an organ of the subject by observing the in-vivo images displayed on the image display device and diagnoses the subject.
Further, there are recently proposed magnetic guide systems for guiding a capsule endoscope in a subject by a magnetic force (refer to, for example, Japanese Laid-open Patent Publication No. 2006-68501). In the magnetic guide systems, the capsule endoscope additionally includes a magnet magnetized in a longitudinal direction of a capsule casing in addition to the imaging function and the radio communication function described above and is guided by an external magnetic field formed by a magnetic field generating device outside of the subject. An image capturing direction of the capsule endoscope is controlled by the external magnetic field of the magnetic field generating device, and the capsule endoscope captures a group of in-vivo images inside of an organ of the subject while changing the image capturing direction in the organ.
However, when the capsule endoscope in a subject is caused to time-sequentially capture a group of in-vivo images while changing the image capturing direction thereof as described above by the external magnetic field, there is a possibility that a group of discontinuous in-vivo images in which overlapping image portions do not exist between the in-vivo images adjacent to each other in time, are captured. More specifically, there is a possibility that out-of-capture portions, which are not captured by the capsule endoscope, exist in an organ in which a group of in-vivo images is captured. As a result, it becomes difficult to observe (examine) inside of an organ of a subject without remaining uncaptured portions.